GMC T Series 1994 Repair Manual page 184

Figure 23— Tightening Pinion Nut
Figure 24— Checking Pinion Preload
6. Preload shims (6).
• It is very important to place shims on pinion
gear stem in proper sequence. The pinion
preload spacer must be assembled first, then
the remaining shims.
7. Pinion into the axle housing.
8. Pinion flange (10).
NOTICE: Refer to "Notice" on page 4B5-1.
9. Washer (11) and old nut (12).
Tighten
Nut (12) to " Specification" while holding the pin­
ion with J 8614-01 (figure 23).
A. The nut until the pinion end play is just tak­
en up. Rotate the pinion while tightening the
nut to seat the bearings. Once there is no
end play in the pinion, the preload torque
should be checked.
F4720
Figure 26— Installing Differential Bearings
B. Remove J 8614-01. Using an inch-pound
torque wrench, check the pinion preload by
rotating the pinion with the wrench (figure
24). Preload should be at or below 2.7 to
3.6 N-m (24 to 32 lbs. in.) on new bearings,
or 1.0 to 1.4 N-m (8 to 12 lbs. in.) for used
bearings.
C. If the preload torque is below the specified
values, continue torquing the nut in small
increments. Check the preload after each
tightening. Each tightening increases the
bearing preload by several pounds. If the
bearing preload is exceeded, the pinion will
have to be removed, and a new collapsible
spacer installed.
D. Once a preload of 2.7 to 3.6 N-m (24 to 32
lbs. in.) has been obtained, rotate the pinion
several times to ensure the bearings have
seated. Recheck the preload and adjust if
necessary.